What’s Vulnerable › Vulnerabilities
CVE-2021-32066
- Severity: high (CVSS 7.4 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 2.9% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2021-08-01 · updated 2026-06-17
- Weakness: CWE-755
Description
An issue was discovered in Ruby through 2.6.7, 2.7.x through 2.7.3, and 3.x through 3.0.1. Net::IMAP does not raise an exception when StartTLS fails with an an unknown response, which might allow man-in-the-middle attackers to bypass the TLS protections by leveraging a network position between the client and the registry to block the StartTLS command, aka a "StartTLS stripping attack."
Affected products
- Oracle Corporation JD Edwards EnterpriseOne Tools: before 9.2.6.1 — fixed in 9.2.6.1
- Ruby: from 2.6.0 through 2.6.7; from 2.7.0 through 2.7.3; from 3.0.0 through 3.0.1
How to fix
Upgrade to a fixed version: Oracle Corporation JD Edwards EnterpriseOne Tools 9.2.6.1. Check the vendor advisory for mitigations.
References
- https://github.com/ruby/ruby/commit/a21a3b7d23704a01d34bd79d09dc37897e00922a
- https://hackerone.com/reports/1178562
- https://lists.debian.org/debian-lts-announce/2021/10/msg00009.html
- https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
- https://security.gentoo.org/glsa/202401-27
- https://security.netapp.com/advisory/ntap-20210902-0004/
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://www.ruby-lang.org/en/news/2021/07/07/starttls-stripping-in-net-imap/
- https://github.com/ruby/ruby/commit/a21a3b7d23704a01d34bd79d09dc37897e00922a
- https://hackerone.com/reports/1178562
- https://lists.debian.org/debian-lts-announce/2021/10/msg00009.html
- https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
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